Method of filling porous receptacles with powdered materials



Dec. 13, 1960 v. l. H. LINHARDT METHOD OF FILLING POROUS RECEPTACLESWITH POWDERED MATERIALS Filed Sept. 8, 1953 FIG. I.

22 l2 lO 70 28 66 FIG. 2.

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nited States Patent 2,964,070 METHoD on FILLING PoRoUs RECEPTACLES wrmrownnann MATEmALs John H. Linhardt, Los Angeles, Calif., assigner toAgrashell, Inc., Easton, Pa., a corporation of Delaware Filed Sept. 8,1953, Ser. No. 378,899

Claims. (Cl. 141-7) This invention relates to a method of an apparatusfor filling containers with tinely divided materials to reduce voidsbetween the fine particles and thereby increase compaction of theparticles with the result that a given quantity of materials can bepacked in less space.

The invention relates more particularly to the handling and packing ofmicron type particles in porous containers as compared to placing largergranular materials such as coffee in non-porous containers.

When packages such as kraft paper bags are used for the packing offinely divided materials under conventional packing methods, there isconsiderable loss in shipment and handling of the bags. This is dueprimarily to compaction as a result of handling in shipment, leaving aconsiderable amount of space which permits the compact material to shiftwith sufficient `force to rupture the bags. Various attempts have beenmade to overcome this difficulty without any appreciable success.Increasing the number of plies in an attempt to increase the strength ofthe bags or other containers is costly and does not solve the problem.

Investigation has shown that conventional packing of finely groundmaterial in paper bags, to 25% of the cubic volume in the bag is freeair. For example, when packing 100 lbs. of a minus 325 mesh material ina2l x 5 x 41" 5-ply open mouth paper bag, the highly aerated material hasa volume of 4305 cubic inches, whereas the volume of 100 lbs. of thematerial itself is only 3360 cubic inches. Therefore the freshly packedbag contains 945 cubic inches of free air. When the filled bag issubjected to pressure such as in stacking of the bags, air is forced outof the bag through pores in the material of the -bag with the resultthat there is a loosely packed product and not a solid package.

lf the product could be packed in such a manner as to remove all freeair the dimensions of the bag could be reduced to 2l x 5" x 32",resulting in a considerable saving in packing cost.

The porosity of container materials such as kraft paper is important inconnection with the Vpractice of my invention. A principal object of theinvention is to support a porous container or bag provided with aconventional inlet valve and known as a valve bag, in a chamber which issubjected to a negative pressure. The free air inside of the bag isexhausted through the porcs therein, thereby reducing the air andpressure within the bag. Then a supply of finely divided material isadmitted to the interior of the bag and is sucked or drawn therein bythe weight of the material fed from a hopper and the atmosphericpressure exerted on the material in the hopper. At the same time theentrained free air entering with the -finely divided material will beexhausted from the bag through the pores in the Walls thereof. Theporosity of the bag is such that it will act as a yfilter permitting theescape of air but retaining the fine particles in the bag.

Not only does material packed according to my invention result in asaving in the quantity of lbag material required for a given quantity ofmaterial packed, but the material is compacted to the extent that itfills substantially all of the volume of the bag and the material isheld against shifting and resultant rupturing of the walls of the bag.`y

Other objects of the method and apparatus will more fully appear fromthe following description in connection with the accompanying drawing. y

Fig. l is a top view of apparatus for practicing the in vention,portions being broken away to vshow interior structure.

Fig. 2 is a side elevational View of the structure of Fig. 1 withportions broken away and in section.

Fig. 3 is an enlarged sectional detail taken approxii mately on the line3-3 of Fig. l.

Figs. 1 and 2 disclose an embodiment of the apparatus and include a baglling chamber 10 including a stationary portion 12 and a door 14 hingedat 16 and secured to the body portion by a -bolt and wing nut unit 18.The main chamber portion 12 is supported by suitable brackets 2t) and22. n

Extending from the upper right hand portion of the chamber 10 is ahousing 24. Located partially within said housing and partially in anupper corner portion of the chamber 10 is a filling spout 26 including ahead 28 and a tubular extension 30. The right hand end of the extension30 is connected by a flexible coupling 32 to a tube 34 leading from thebottom of a material hopper 36. A shut-off valve 38 is located in thetube 34.

The filling spout 26 is connected to a pair of leaf springs 4d. Asviewed in Figs. l and 2 the left ends of the springs 40 are connected tostuds 42 extending from opposite sides of the spout assembly 26 and theright ends of the springs are secured by bolts 44 to posts 46 whichextend upwardly from the bottom of the housing 24. Straps `48 lie aboutthe right end portion of the tubular extension 30 of the spout 26 andengage the leaf springs 40. As a result of the spring mounting of thespout 26, when Weight is applied to the bag lling head 28 to asufficient degree the entire spout assembly will tilt counter-clockwiseas viewed in Fig. 2.

Located in the housing 24 is a normally closed switch 50 having a switcharm 52 adapted to be engaged by an adjustable stud 54 mounted on thelower side of the tubular extension 30 of the lling spout 26. The switch50 in turn will close a solenoid valve 38 at the bottom of the hopper 36and simultaneously close a solenoid Valve 53 which is located between avacuum pump 55 and the lower portion of the chamber 10. There is aconduit 56 from the vacuum pump 55, through the solenoid valve 53 and afilter 58 to the interior of said chamber 10.

The left portion of the filler spout 26 comprises a filler head 28mentioned above. This filler head has a hollow portion 60 and a closedend 62. The hollow portion is provided with elongated laterally disposedoutlet openings 64 having deflectors 66 along their upper edges todirect finely divided material from the hopper 36 into a bag 618 whichis supported on the filler head.

The filler head 2S is provided with a pair of resiliently mounted hooks70 for a purpose to be described below.

When a bag is to be filled, the door 14 of the casing 10 is opened and acontainer such as the bag 68 is placed in the chamber 10, the fillerhead 28 being inserted through a valve 72 formed in an upper corner ofthe bag in a manner known in the tart. It will be noted that the fillerhead 28 has a flared skirt 74 which assists in forming a seal betweenthe bag valve 72 and said filler head.

When the bag is placed in position `and prior to filling the ller spout26 is held horizontally or with the filler spout 28 tilted slightlyupwardly and supported by the leaf springs 40. When the door 14 isclosed it will strike a normally open switch unit 76 and close theelectrical control circuit to open the solenoid valve 38 and actuate thevacuum pump 55 which exhausts air from within the chamber 10. It isdesirable that a seal or gasket 79 be provided between the door 14 andthe main casing portion 12.

The solenoid valve 53 is connected to a timing switch 78, the switchcausing the valve 53 to open to atmosphere and create a pulsatingpumping action to exhaust air Kfrom the chamber 10.

As pressure within the chamber l is reduced, it will draw air throughthe walls of the bag 68 which is formed of a porous material. Thismaterial may, for example, be a suitable kraft paper which Will pass airtherethrough but will retain highly divided particles of the materialwith which the bag is to be iilled.

Since the iiller spout 26 is in its upper position supported by thesprings 40, the switch 50 is closed since the stud S4 on the fillerspout is not in engagement with the arm 52 which is adapted to open theswitch 50 when the ller head 28 is tilted down under the weight of 'aiilled bag. Since the switch 50 is closed at the beginning of theiilling operation, the solenoid valve 38 is held open to permit the flowof iinely divided material from the hopper 36 through the tube 34 andfiller spout 2.6 into the bag 68.

During the initial operation of the vacuum pump 55, air is to aconsiderable extent exhausted from the bag L68. As this occurs, negativepressure builds up in the bag and this pressure is exerted through thefiller spout to the hopper 36 to suck or draw finely divided materialthrough the filler spout and into the bag. As the material flows intothe bag it carries with it a certain amount of entrained air which isdrawn from the bag 68 through the pores in its walls.

By reason of the removal of air from the interior of the bag through thepores of the bag material, air is removed from the voids in thematerial, causing the micron particles to settle into the bag with aconsiderable degree of compaction so that when the bag is lled there isa minimum of air in the bag and practically all of its interior volumeis iilled with the compacted micron particles.

When the bag is iilled, the weight of the material in the bag willcreate a downward pull on the iller spout and tlex the leaf springsdownwardly. Thereupon the stud 54 on the bottom of the ller spout 26will actuate the switch arm 52, breaking the electrical circuit. Thisresults in closing of the solenoid valve 38 and stopping of the vacuumpump 5S.

When the bag 68 is filled `and the iiller head 28 drops down, openingthe switch 50, the solenoid valve 53 will be actuated to vent toatmosphere, thereby breaking the vacuum in the chamber 10 and permittingdoor 14 to be opened. Othewise the reduced pressure in the chamber 10would hold the door 14 tightly closed and prevent it from being openedfor the removal of the filled bag.

When the chamber 10 is opened, the switch element 76 will open theelectrical circuit in another place so that when the lled bag is removedfrom the ller head 28 and the ller spout is permitted to return to itsupper position, the vacuum pump will not be energized and the solenoidvalve 38 will not be opened until .the casing door 14 is again closed.

It will be noted that the bag valve 72 is folded so that it projectsinto the bag in the position shown in `Fig. 2. When a lled bag isremoved from the filler head 28, the hooks 70 will engage the inwardlydirected edge of the bag valve and pull the valve out so it can beclosed by stitching or other suitable means.

It should be remembered that the apparatus and method disclosed hereinare intended to be utilized with the filling of containers such as bagshaving porous walls with extremely finely divided materials. Theinvention is not to be confused with vacuum packing of non-porous abovethe general objects of the invention are to provide a method and meanswhereby very iinely divided materials can be compactly placed in porouscontainers so that the size of the container in relation to the amountof material packed can be considerably reduced and the damage usually-resulting from the handling and shipment of bags conventionally iilledwith linely divided materials is reduced to a minimum. The iilling ofbags in accordance with the invention reduces shipping and storage spaceto a considerable degree. Also, when expendable pallets are used forshipping, the size of the pallets and the number required for a givenquantity of material shipped can be greatly reduced.

With regard to savings in shipment, it has been found that it isnecessary to use a titty-foot box car to load 800 containers weighing100 lbs. each. The same product, packed in containers in accordance withthe invention, can be loaded in the same quantity and at the same depthin a forty-foot box oar. Mention is made of the Same depth of loadbecause too great a weight imposed upon bags in lower layers is ofcourse objectionable.

The purpose of the solenoid valve 52 is not only to vent the chamber 10,but also, with the aid of the timing switch 78, to vent the vacuum pump55 to :atmosphere While maintaining reduced pressure in the chamber 10,thereby creating a pulsation in the suction applied by the pump to theinterior of the chamber 10. This results in what might be termed acamping action on the material being introduced into the bag 68 andincreasing the compaction of materials therein.

Another advantage of packing finely divided material according to theinvention is that the bag can be lilled and made to conform to a more orless rectangular shape, greatly improving storing and loadingoperations.

Ethciency of packing or time required to fill a bag can be controlled byvarying lthe porosity of the material from which the package is formed.

Still another important advantage of the invention resides in the tactthat tension or stress on the plies of multi-wall paper bags isdistributed more evenly to all the plies to provide a stronger package,a condition which does not exist when multiple ply bags are tilled inthe conventional manner.

It will be understood that various changes can be made in the form anddetails of the apparatus and in the specific steps of the methoddisclosed herein without departing from the spirit of the invention.

I claim:

1. An apparatus for lling porous containers with finely dividedmaterials which includes a substantially closed chamber having an inletfor the introduction of the finely divided material and an airexhausting outlet, a

, iiller member comprising a material supply conduit extending into saidchamber through said inlet, said chamber comprising a housing having amovable closure, an :air suction device connected to the outlet of thechamber to exhaust air therefrom, and a control device interposed 1between the main body of the chamber and the movable closure andconnected to the suction device and operative upon movement of theclosure to its closed position to render the suction device operative.

2. Apparatus for lilling porous bags having bag valves incorporatedtherein which includes a reduced pressure chamber for receiving a bag tobe iilled, a filler head in said chamber having means for connectionwith a supply of material to be packed, said head having a free endentrant into a bag through the bag valve, said tiller head having amaterial discharge opening adjacent its free end, and a lateralprojection adjacent the free end of the filler head to engage the bagvalve and pull it outwardly relative to the bag proper when the head isremoved from the bag.

3. Apparatus for iilling porous containers with nely divided materialswhich includes a substantially closed chamber having an inlet for theintroduction of the finely containers, with larger granular materials.As stated 75 divided materialsfsaid chamber having an air exhaustingoutlet, =a iiller member comprising a supply conduit extending into saidchamber through said inlet `and terminating in the chamber above thebottom thereof, said filler member lying generally horizontally in saidchamber and providing a support for a container to be lled, an airsuction device connected to the outlet of the chamber to exhaust airtherefrom, a portion of the liller member in said chamber beingdownwardly yieldable under a predetermined weight, said supply conduithaving a material flow control valve therein, a control device having aconnection with the material flow control valve to open and close thevalve, and said filler member being movable to actuate said controldevice.

4. A method of packaging finely divided materials in exible containersof porous materials which includes supporting the containers by theirtops in a vertical position, introducing the finely divided materialsinto the tops of the containers through -an inlet of considerably lesscross section than that of the containers while said containers aresubjected to pulsating negative air pressures on the exteriors thereofduring the filling operation, and producing with the pulsating negativepressures a maintained withdrawal of Iair from the containers throughthe pores of the bottom and sides thereof with a resultant compaction ofthe iinely divided materials in the containers.

5. Apparatus for lling exible porous containers with finely powderedmaterials which includes a substantially closed chamber, an inlet forthe introduction of air and finely divided material including a spoutextending into said chamber and located in the upper portion thereof,said spout having a portion upon which -a container can be hung andsupported in said chamber, said chamber having an air-exhausting outlet,an air suction device having a connection with said air-exhaustingoutlet to exhaust air from the chamber, and `an air pulsator in theconnection between the chamber outlet and said suction device.

References Cited in the iile of this patent UNITED STATES PATENTS862,231 Bates Aug. 6, 1907 1,037,824 Fasting Sept. 3, 1912 1,782,733Lilly Nov. 25, 1930 2,347,431 Pauly Apr. 25, 1944 2,381,454 Huth Aug. 7,1945 2,488,395 Goldberg Nov. 15, 1949 2,596,807 Dippel May 13, 19522,613,864 Carter Oct. 14, 1952 2,650,011 Anderson Aug. 25, 19532,730,282 Bonner Ian. 10, 1956 2,738,119 Haygarth Mar. 13, 1956 FOREIGNPATENTS 610,220 Germany Mar. 6, 1935

